The present invention relates to devices arranged on the doors for automatic closing of the door. More particularly, the invention relates to a bar structure for the device for automatic closing the door.
In conventional devices of the type under consideration adjusting bar arrangements are utilized for a connection between the shaft of the upper door lock and the door wing or door frame, these arrangements including a main arm and an adjusting arm pivotally connected to the main arm, the adjusting arm having a receiving bar and an adjusting bar adjustably connected to the receiving bar.
The bar structure devices for door locks are adjustable within a wide range so that they can be utilized in various situations and adjusted to various slipping depths and various joint dislocations which result from various width of the doors.
It has been known that for adjusting the bar structure of a door lock, the adjusting bar of the adjusting arm was formed with an outer thread whereas the receiving bar was provided with the inner thread. In order to adjust the adjusting arm to a required position it was necessary that the bar structure of the adjusting arm together with the hinge had to be separated from the door wing or door frame and then the adjusting arm had to be displaced relative to the receiving arm. The described operation was time-consuming.
In other known constructions of the bar structures of the door locks, the adjusting bar and receiving bar were allowed to be displaced one relative to another, but in these constructions each bar was provided with a row of openings for receiving bolts which connected the both bars in any selected position. The disadvantage of these constructions is that, on the one hand, a plurality openings required for locking the bars in position substantially weakened the structure, and, on the other hand, the adjusting process was time consuming because the connecting bolts should be totally released and removed from the openings in order to adjust the position of the adjusting bar relative to the outer receiving bar.